running ipv6

[...]... 5270_c01_final.qxd 12 10/1/05 10:56 AM Page 12 CHAPTER 1 ■ IPV6 IP Version 6 Last but not least, there is IPv6 There are many differences between IPv4 and IPv6, but it’s important to recognize that IPv6 is still IP Any and all protocols that run over IPv4 can also run over IPv6, assuming the necessary changes are made to accommodate the larger addresses IPv6 addresses are 128 bits (16 bytes) long and fully... protocol, not to bombard the reader with unnecessary details This means that the book covers the IPv6 specifications to the degree necessary to successfully operate an IPv6 network; for a detailed discussion of the IPv6 protocol itself, see IPv6 Essentials by Silvia Hagen (O’Reilly & Associates, 2002) or IPv6: The New Internet Protocol (Second Edition) by Christian Huitema (Prentice Hall, 1998) Alternatively,... to support IPv6, the transition to IPv6 will indeed be expensive However, having to replace hardware is a problem mostly with very big routers used by Internet Service Providers and large enterprises If these routers have special hardware support for routing IPv4 that isn’t compatible with IPv6, the router is either completely useless for IPv6 or performance is dramatically lower because IPv6 must be... (http://www.ipv6tf.org), Spanish IPv6 Task Force, and the IPv6 Task Force Steering Committee He participates in several European and worldwide IPv6 Task Forces and related activities ■PIM VAN PELT is a network and (UNIX) system administrator and programmer based in the Netherlands As a youngster, he lived in the U.S and in England, and more recently, he has lived in Belgium He got exposed to IPv6 in college... through manual configuration and using an IPv6 version of the Dynamic Host Configuration Protocol (DHCP) Because the host bits in the IPv6 address don’t necessarily contain a MAC address, IPv6 includes an ARP-like mechanism to discover MAC addresses But ARP is a fairly Ethernet-specific protocol, and it uses broadcasts, which IPv6 doesn’t support Instead, IPv6 uses multicasts extensively Multicasts... was published in 1995 (with many more to come) The main difference between IPv4 and IPv6 is that IPv6 uses addresses that are 128 bits, rather than the 32 bits in IPv4, allowing no less than 3.4 × 1038 individual addresses See Appendix A for an overview of the IETF standards process and a list of IPv6- related RFCs IPv6 Benefits When the IETF set out to create “IPng,” the Internet Protocol next generation,... addresses Efficiency IPv6 processing is more efficient than IPv4 processing in many ways This boost in efficiency is illustrated by the fact that while the address fields are now four times as big as in IPv4, the total size of the IPv6 header that precedes all packets is only 40 bytes, twice as big as the typical 20-byte IPv4 header Efficiency improvements in IPv6 include the following: • The IPv6 header has... 7 for additional details on IPv6 advantages and transition issues and Chapter 8 for more information on how IPv6 works internally Myths A number of myths surround IPv6 Some are simple misinformation, but others are more persistent because they have small kernel of truth to them, which is then blown out of proportion Security Probably the most persistent myth surrounding IPv6 is that it would be more... IPv4, it’s still easier to run IPsec in IPv6 IPv6 does have one security advantage over IPv4, though: in IPv6, an Ethernet usually gets 64 bits to number hosts With IPv4, this is never more than 16 bits and is often much less This means that an attacker or a worm looking for something to hack or infect has a much harder time scanning even a single Ethernet subnet in IPv6 than scanning the entire IPv4 Internet... implementations, while it’s often still lacking in IPv6 implementations because the Mobile IPv6 standard hasn’t quite settled yet Quality of Service It is often said that IPv6 has better support to provide for additional “quality of service” (QoS), or in other words, mechanisms to prioritize certain traffic over other traffic This is not the case IPv4 and IPv6 both support traffic prioritization by using . European Commission IPv6 Task Force (http://www.ipv6tf.org), Spanish IPv6 Task Force, and the IPv6 Task Force Steering Committee. He participates in several European and worldwide IPv6 Task Forces.